Unclear on the functionality of --only-missing for media regenerate

[ethanclevenger91]

Issue: Missing image sizes not regenerated
Environments tested: Windows 10 w/ PHP 5.6.16, Homestead vagrant box w/ PHP 7.0.2

To reproduce:

1. Upload images through WordPress media uploader
2. Define a new image size in theme's functions.php
3. Run wp media regenerate --only-missing

Expected result: Image size added in step 2 is generated for all images
Actual result: No thumbnail regeneration needed for "[image-name]" (ID [image-id]). output for all images

Is this as intended or perhaps a bug?

[danielbachhuber]

Sorry for the late reply, @ethanclevenger91.

I was able to reproduce your situation, although I'm not 100% clear on the expected behavior. WP-CLI's current behavior is to look at the sizes stored in attachment metadata, and generate image files for the sizes where the file doesn't exist.

I suppose we could also check the registered intermediate sizes too, but I'm not confident this wouldn't introduce unexpected behavior.

Thoughts?

[ethanclevenger91]

Depends on what kind of unexpected behavior you're potentially foreseeing. In my experience, I'm almost exclusively using intermediate sizes that I've declared rather than the built-in ones.